I will attempt to answer this from another perspective that has demonstrated merit to its claims: Ayurveda. Ayurveda categorizes food into three groups: satvik, rajasik and tamasik, in gradation of the effect it has on the human body after consumption, and the energies it fuels. Satvik foods bring about harmony - they do not disturb the natural ecosystem in any way. These include macrobiotic foods, grains, legumes, berries, vitamin-rich fruits and vegetables that grow above the soil. Rajasik foods are not all unfavorable, but have to be consumed in moderation as they influence several physiological functions favorably and are beneficial in many ways. These include dairy, eggs, and root vegetables. Tamasik foods are generally seen as unfavorable for human consumption, as regular consumption can cause several unwanted reactions in the human body, i.e., meat, mood-altering substances, caffeine, etc.

Ayurveda also preaches fasting: "Langhanam param oushadham", which essentially means fasting is the best medicine. This voluntary detoxification helps the body rejuvenate, regain optimum performance of all its faculties as well as re-energize overall functioning.

These offer a direct link between food and religion as far as Hinduism is concerned (as well as Jainism and Buddhism to a large degree), in that they inform the karmic cycle that the faith preaches as the major governing force.

Please also refer to another question I have attempted to answer, link below.

Source: Personal experience and opinion. None of this is intended as dietary advice, and my own experience has been guided by careful informed opinion rather than self-experimentation.

Various religions have certain food-related laws that are meant to be followed based on several factors: cleanliness, association, fasting, etc.

For example, Catholics are not supposed to eat meat on Fridays as a way to offer a small sacrifice. Jews are not to eat shellfish or pork based on the idea that they are unclean animals, and they are also not supposed to eat dairy with meat because birth (milk) and death (meat) should not enter the body together. Buddhists are generally vegetarian because they believe that to take part in the suffering of any sentient being will create bad karma.

Fasting holidays such as the Baha'i moth of Ala, the Hindu day of Ekadasi, the Muslim month of Ramadan, the Chauvihar Upwas of Jainism, and the Jewish day of Yom Kippur are considered holy days of meditation and prayer which require fasting of food and water.